Resuscitator



4. J. H. EMERSON ETAL RESUSCITATOR hm@ M,

3 Sheets-Sheet l Filed April 15, 1946 ZAWEA 6 Mmm@ M9 H949. J. H. EMERSON ET AL RESUSCITATOR 3 sheets-sheet 2 Filed April 1.3, 1946 HIllIl Emme M, W49. J. H. EMERSON ET AL RESUSCITATOR 3 Shees-Sheet 3 Filed April 15, 1946 Q Maf Patented June 14, 1949 UNITED STATES PATENT OFFlCE 2,473,416 RESUSCITATOR Emerson, Cambridge, and George J.

Lexington, Mass.;

John H.

Sinnett, or to said Emerson Application April 13, 1946, Serial No. 661,937 8 Claims. (Cl. 12S- 29) This invention relates to apparatus for and a method of treating persons unable to breathe normally, for example those suffering from asphyxiation, shock, or extreme weakness due to illness, surgical operations or the like.

It has heretofore been proposed to produce artificial respiration by means of apparatus designed automatically to inflate the patients lung by supplying a reviviiying gas, for instance oxygen, air or the like under pressure, to the lung, and then to deiiate the lung by a suction action so as positively to withdraw gases therefrom. Apparatus of this general type is illustrated, for example, in the patent to Sinnett No. 2,268,172, dated December 30, 1941. The patented apparatus comprises a fluid-pressure motor, aspirating means, and valves automatically operated by the motor in response to changes in lung pressure. While apparatus of this type is very desirable, it is somewhat complicated and expensive to build. Moreover, there has been some criticism of this type of apparatus on the ground that the suction effect is harmful to the patient.

While we have discovered no evidence that the use of suction, properly controlled, is injurious, we do believe it desirable to provide simpler and less expensive apparatus than that customarily used in the pressure-suction system. Accordingly, one object of the present invention is to provide simple and relatively inexpensive apparatus operative automatically to maintain artificial respiration in response solely to the positive pressure oi the gas supplied and to the contractile force of the patients chest. A further object is to provide apparatus of light weight and compact construction, such that it may readily be worn by the user as a portable breathing device, for instance by persons obliged to work in air contaminated with poisonous gases or filled with smoke.

A further object is to provide apparatus of automatic type operative to inflate the lungs, even of an unconscious patient, in response to the direct pressure of the gas supplied, and which responds to a predetermined lung pressure, thereby automatically to cut off the gas from the supply and concomitantly to open free passage between the lungs and the atmosphere, or at least from the lungs to a space in which the pressure is lower than that or the gas supplied but not below that oi the atmosphere. Other and further objects and advantages of the invention will be pointed out in the following more detailed description, and by reference to the accompanying drawings, wherein Fig. 1 is a side elevation of the complete apsaid Sinnett assignparatus shown connected by a exible conduit to a gas supply tank (the latter being broken away) Fig. 2 is a rear elevation oi the resuscitator device with the outer housing removed;

Fig. 3 is a front elevation of the in Fig. 2;

Fig. 4 is a front elevation of the resuscitator with the inner cap removed to expose the motor mechanism; L

Fig. 5 is a side elevation with the cap broken away and with the valve housing in vertical section substantially on the line 5-5 of Fig. 2;

Fig. 6 is a horizontal section substantially on the line (i-S of Fig. 2 showing the inlet valve open and the exhaust valve closed;

Fig. 7 is a view similar to Fig. 6 valves in reversed position;

Fig. 3 is a side elevation of apparatus embodying a slight modification;

Fig. 9 is a rear view of the resuscitator of Fig. 8 with the housing removed;

Fig. 10 is a side elevation of the in Fig. 9,

Fig. 11 is a fragmentary section, substantially on the line I l-l l of Fig. 9, showing the inlet valve open and the exhaust valve closed;

Fig. 12 is a view similar to Fig. 11, but the valves reversed; and

Fig. 13 is a front elevation of the device of Fig. 10, with the cap removed to expose the motor mechanism.

The apparatus of the present invention as herein disclosed generally resembles and embodies certain desirable features of the apparatus disclosed in the patent to Emerson No. 2,364,626, dated December 12, 1944. As in the patented device, the effective operation of the apparatus herein disclosed requires a source of gas at superatmospheric pressure, preferably at a substantially constant pressure. When herein reference is made to a gas, gaseous iiuid or the l'ke, such terms are used without limiting intent, being broadly inclusive oi pure gases, for example, O2 as well as mixtures of gases, for example, atmospheric air. As here illustrated, a source of gas under superatrnospheric pressure is provided by the tank l; for example, a conventional commercial oxygen tank having a fitting 2 provided with a valve controlled by the handle 3, a pressure gauge 4 and an outlet nipple to which one end of the iiexible conduit 5 is secured. While a commercial gas tank may be employed as the source of gas under pressure, it is contemplated that air may be supplied under pressure to the resuscitator apparatus, for example from a tank of compressed air device shown but showing the device shown showing or by means of a hand or power-driven pump cured to the arms 3| and 32 forming parts of a preferably supplying the air to a tank or reserrigid actuating yoke. The upper ends of the voir of substantial capacity in order that the air arms 3| and 32 are pivotally secured by means delivered to the resuscitator device may be at a or" screws 33 and 34, respectively, to bosses 35 substantially constant superatmospheric pressure. 5 and 36 projecting forwardly from the ring l2.

all contained in the two-piece housing comprisby a ti ansverse bar 3l (Fig 5) and also by a bridge ing the parts` 6 and i which may be of sheetv piece 38, the central portion of the bridge piece metal, molded plastic or the like, and which prefbeing spaced forwardly from thebar 311 to proerably have telescoping engagement at their lo] vide a chamber for the reception of the closed meeting edges and which are normally connected end Se of a U-shaped toggle link 40. The upper by screws 8 or the like. This housing is hollow ends'of the opposed legs of this toggle link 40 the face mask M or equivalent device such as a 15 to thebracket arms il and 42, and the closed upbreathing tube by means of which the gask is de per end lill (Fig 4) of this toggle link 43 embraces livered to the patient. As illustrated, the face a rigid 100St Ll5 projecting forwardly flOm the ring mask M is detachably secured to the resuscitator i2- The upper end 46 0f e C011d tellSlOIl Spring proper by means of a rigid telescopic connection, @l 1S secured to a transverse rod 4Ba uniting the andthe Weight ofthe resuscitator-i'ssmall enough 20 spaced iegsf the toggle link 43-` at a" point just so that when apatient reclines, his face may combelOW the 100St' 45- The lower end Off theA Spring fortablyfsupport the entireresuscitator device ex- W S 0011119015661 t0 all adjustable $121101A 48" which clusi've of the gas'supply, theweightof'the device DQ'SSGS through an Opening in. the Closed end 3,9 being distributed over the area of his face by 2.- 0i the toggle link 40. .means of the mask. D The bracket arms 4| andl l2` are; parts of a Allof the operative mechanism of. the resusci- Subsianially U-Shaped member whose centralv ta-.tordevcezisA carried oy-av rigid` casting 9% (Fig Port-1011 rigidly @Dime-Oiled t0 ay rigid' disk 49 5) which may, for examplel be of mena] molded (Fig 5) disposed at the forward side of the diaproyjded with a. depressed. portion 9a. (Fig 5) 30 at the rear side of thediaphragm side Il andI sensitively responsive to lung pressure- The edges Uasmg through an aperture H1 a rigid bridge of this disk-shaped diaphragm H aresecured to member 55 (F 1g 2) attached by SCIGWS 56 (Fig 2) the casting 9 by the clamping ring l2 which is o the rer 51de 0f the Castlng held in placefbyy screwsrivets, or the:A like. 40 A housmg block' 57 (FgSj 5; Gand?) is'secured b uia'rstem is (Figi) 'offthefmeskMwitheteie end 0f a lgdl cmdut G2 Whose lower end is SCDDlng; t so.l that the:.mask;may readily be re- 50 lvleghwlthda nipple G3i-F1@ 21) PPIIB recep' moved from the resuscitator if desired The tu-v o e en of the exlble condult 5 The 6X The casting or base; member 9y is provided' at 5v a suitable oo nduit not Shown t0 Some restricted ber l5. The* chamber 2l: has a rear'iwall 23 hav- 60 The Cap .i3 is provided with an inlet Orifice 55 aperture'fororifice deinedbya conical valveseat 65 to irihalatO-n by the patient' The Cap is 3150 nulair seat.: deiiingthe orifice" in the wall.v 24 7o thelexhaust valve 25 is provided with az-stem 28 Thesevalve steinsare connected, respectively Refer ady described. The resuscitator comprisesea base-'casting 9l (Fig. 13')` like that above described, which, together with the flexible diaphragm II and the cap I3, defines an atmospheric pressure chamber and a motor chamber like those above described. In this instance the casting or base member 9 is provided with an elongate boss 2I'ia (Figs. 1l. and 12) having the inlet chamber 2|a and the exhaust chamber 22, The inlet valve comprises an annular member 25 which may be of rubber, fiber or the like and whose fiat forward face is designed to engage the rear face of the boss a so as to close the entrance to the chamber 2 Ia when the member 25a engages the rear surface of the boss. This member a is loosely mounted on the valve stern 21a, the latter having a retaining head 66 at its rear end. The forward end of the exhaust chamber 22a is shaped to provide a rearwardly convergent or beveled valve seat which cooperates with the valve 26 carried by the stems 282A. The valve stems are secured to the arms 29a and 30EL (Fig. 13) respectively, of an actuating yoke, the lower ends of the yoke arms being pivoted by screws a and 36a to bosses projecting forwardly from the ring I2. The toggle link has its closed lower end arranged to embrace a fixed stud a projecting from the ring I2, and the lower end of a coiled tension spring 41 is secured to a crossbar 46b connecting the legs of the link 40 just above the stud 45a. The opposite end of the spring 41 is secured to an adjustable stud 48a passing through an opening in the closed upper end 44 of a second toggle link 43. The adjacent ends of the toggle arms are pivotally connected to the bracket members 4I and 42 which project forwardly from a disk 49 disposed at the front face of the diaphragm II. A spring 5 Ix (Fig. 10) generally similar to the spring 5I above described, bears at its forward end against the disk at the rear of the diaphragm, the rear end of this spring engaging a shoulder carried by an adjustable stud 542i which passes through an aperture in a bridge-piece B.

A housing B1 (Figs. 11 and 12) is secured to the rear side of the boss 2liab and denes an inlet chamber 68 which is connected by a rigid pipe 69 to the flexible conduit 5 (Fig. 8) which leads from the gas tank la. A rigid conduit 1I (Fig. 12) is connected to the rear side of the boss 22a and arranged to conduct exhaust gases from the exhaust chamber 22a. This conduit 1I may terminate within the outer housing or it may lead to some other point, for example to a container in which a uniform pressure is maintained, slightly above atmospheric pressure but below that of the gas tank I.

As illustrated in Fig. 8, the tank Iab is provided with a strap 1?. by which it may be carried, for example over the shoulder of the user, and the resuscitator housing is provided with a spring clip or clasp 13 by means of which it may be attached to the clothing of the user. for instance, when the device is used as a respirator in an atmosphere filled with `smoke or poisonous fumes.

Referring again to Figs. 1 to 7, it is assumed that the spring 5I has been adjusted by turning the nut 54a so that the diaphragm II normally occupies the position shown in Fig. 6 when no gas is being supplied from the gas tank. In this position the valve 25 is unseated and the valve 26 is seated. Assuming that gas from the tank I is now admitted under a predetermined reduced pressure to enter the chamber 59, the gas will pass through the port controlled by the valve 25 and into the motor chamber I5, and thence directly into the lungs of the patient. The gas at this predetermined pressure inflates the patients lungs and builds up pressure therein until a predetermined lung pressure (and like pressure in automatic and patent to chamber I5) has beenv attained. The area of the diaphragm is such relative to the strength of the spring 5I that when this predetermined lung pressure is reached, the diaphragm will move rearwardly to the position shown in Fig. 7. In so moving, it moves the brackets 4I and 62 and thus causes the toggle 4mechanism to snap rearwardly, thus quickly moving the valves 25 and 26 rearwardly so as to close the inlet port and to open the exhaust port. The constrictive force of the patients chest now expels gaseous materials from the lungs through the mask, the passage P, the' chamber I5, and the exhaust valve and exhaust port 64. This continues until the lung pressure has dropped to a predetermined amount which should be slightly above atmospheric pressure, whereupon the spring 5I reasserts itself, pushes the diaphragm forwardly, and by the toggle mechanism reopens the inlet valve and closes the exhaust valve, whereupon the cycle is repeated.

The operation of the arrangement shown in Figs. 8 to 13 is slightly different in respect to the fact that the rearward movement of the diaphragm in response to a predetermined lung pressure causes both valves 25a and 26a to move forwardly. However, in so moving the inlet valve is closed and the exhaust valve is opened, the same as' above described, thus permitting the air from the lung to exhaust direct to the atmosphere. Under some conditions one of these arrangements may be preferred and under other conditions the second arrangement may be preferable, it being noted that each of these mechanisms responds to the pressure of the supply gas to admit gas freely to the patients lungs, and then responds to a predetermined lung pressure to cut ofi the supply of gas from the source and exhaust air from the lungs down to but not below atmospheric pressure.

Thus, with either arrangement, the lung pressure is always positive, no suction effect is developed within the lung so that no injurious effects can possibly occur from any suction action, while, on the other hand, the device is completely does not require the assistance of an operator in causing the device to perform its normal cycle.

While a toggle and spring constitutes desirable means for effecting a the valves, it is contemplated that equivalent snap action means may be employed, for instance, means such as is employed in snap action electrical switches, for example, in a so-called Mu or Micro switch, or one such as disclosed in Shaw No. 2,170,341, August 22, 1939,

This method of inating and deflating the lung automatically is apparently novel, and while two forms of apparatus have herein been illustrated whereby this method may be carried into effect, it is contemplated that the method may be performed automatically by other apparatus, or by the use of hand-actuated instrumentalities if desired.

The cycle of operations thus consists in admitting gas under pressure to the patients lung, so as thereby to inflate the lung; automatically shutting oif the gas from the supply as soon as the lung pressure reaches a predetermined value and at the same time providing a free passage from the lung to the atmosphere; and then when the lung pressure has fallen to a predetermined value, not less than atmospheric, in response to chest contraction (natural or artificially induced) again admitting gas from the supply, automatically to initiate a new cycle.

vIn the description some reference has been made to the "'upper and device and to the lower lparts of the ront `and rear, but these while it has been suggested that air or oxygen may be supplied in this way to the patient, it is l. Breathing apparatus of the kind wherein gas under pressure ilating the lungs and having a case which houses all of the one is closed the o .supplies the energy for ina face mask and ther is open, and Vice versa,

and mechanical connections operative to transmit motion from the movable wall of the pressure motor to said valves, the motor and actuating mechanism being lconstructed and arranged to open the inlet passage determined thereby to admit gas from the in response to a prelung pressure Supply,

superatmospheric lung pressure.

2. Breathing apparatus of the kind wherein gas under pressure supplies the `energy for inchamber, and mechanism for transmitting motion from the pressure-responsive element of the motor` to the valves, said mechanism including a spring operative no passage, the valves rmally to hold the inlet valve are suddenly reversed so as to close the inlet passage and open the exahaust passage.

vsaid chamber, `means within the haust valve .1s seated by moving away from said chamber, and snap-action mechanism for trans'- mi-tting motion lfrom the pressure-responsive ele- -dei-ined by a valve seat, a valve cooperable with each seat respectively,

and mechanism for transmitting motion from the pressure-responsive element of the motor 4to the valves, said mechanism including a toggle-linkage and a spring, and means so connecting the valves -to the toggle-linkas normally `to hold the toggle-linkage in a position to keep the inlet valve open, and the pressure-responsive element of the motor being `of such area that in response to a predetermined with each seat respectively, and snap-action mechanism for transmitting motion from the pressure-responsive element of the motor to the valves, sai-d mechanism including an open coil lung pressure at which exhalation shall begin, and means so connecting the valves to said mechanism that When one valve is open the other is closed, and vice versa, the strength of the spring being so related to the area of the pressure-responsive element of the motor that When the lung pressure has been built up to a predetermined value, in response to the admission of gas through the inlet passage, the snap-action mechanism Will suddenly close the inlet and open the exhaust valves, the area of the pressure-responsive element of the motor being such that when the lung pressure drops to a lesser predetermined value, greater than atmospheric pressure, the mechanism will open the inlet valve and close the exhaust valve.

6. Breathing apparatus o the kind Which inlates the patients lung by the admission of gas at superatmospheric pressure and which allows the lung to deate in response to chest contraction alone, said apparatus including a gas admission valve and a gas exhaust valve and means for automatically actuating said valves, cycle after cycle, including a spring tending normally to hold the inlet valve open and a pressure motor which is responsive to lung pressure, and snapaction mechanism actuated by the pressure motor and operative to close and to open the inlet and exhaust valves, said mechanism being so designed and arranged that when the inlet valve closes the exhaust valve simultaneously opens.

7. In a resuscitator oi the kind wherein gas under pressure supplies energy ior iniiating the lung and having a face mask rigidly connected to a case of a size such that it may be held in the palm of one hand and which houses all of the operative mechanism of the resuscitator and which has connected thereto one end of a single flexible supply conduit through which gas under pressure is supplied from a suitable source, means Within the case deiining a motor chamber having a movable Wall, said motor chamber communicating freely at all times with the interior oi the mask, means providing an exhaust passage leading rom said motor chamber to the atmosphere, a valve controlling the admission of gas from the supply conduit to the motor chamber and a valve controlling the discharge of gas from the motor chamber to the atmosphere, and mechanical means for transmitting motion from the movable wall of the motor chamber to said valves, said movable Wall being responsive to a predetermined superatmospheric lung pressure to open the inlet and to close the exhaust valve, and being responsive to a greater predetermined superatmospheric lung pressure to open the eX- haust valve and to close the inlet valve.

8. Breathing apparatus of the kind wherein gas under pressure supplies the energy for innating the lungs and having a case which houses all of the operating mechanism of the resuscitator, said case having therein a motor chamber provided With a movable Wall, a supply conduit leading from a source of gas under superatmospheric pressure, a breathing conduit leading to the patients lungs, an inlet valve controlling a passage leading from the supply conduit to the breathing conduit, an exhaust valve controlling an exhaust passage leading from the breathing conduit to a passage in which the pressure is approximately atmospheric, and mechanical means within the case for transmitting motion directly from the movable Wall of the motor chamber to the inlet and exhaust valves, the transmission means being so constructed and arranged that when the inlet valve is closed, the exhaust valve is open and vice-versa, the movable wall being responsive to a predetermined superatmospheric lung pressure to open the inlet valve and to close the exhaust valve, said wall also being responsive to a greater predetermined superatmospheric lung pressure to close the inlet valve and to open the exhaust valve.

JOHN H. EMERSON. GEORGE J. SINNETT.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

